The goal of the proposed project is to investigate the stability of individual differences in infants' allocation of attentional resources, and to determine whether infants at risk for later cognitive and attentional deficits have difficulty maintaining their attentional focus. Infants learn about their world by attending to the environment around them. Novel events that occur, however, may distract their focus. Thus, infants must develop the ability to maintain their attentional focus to important stimuli, and ignore unimportant irrelevant ones. Previous research suggests that the ability to allocate attentional resources in this way develops considerably during the first year of life. Moreover, individual differences in these abilities may exist in infancy. Such individual differences would have serious consequences for infants' acquisition of information about the world. If infants are easily distracted, they will be less able to maintain their attention to novel objects, events, and people, and learn about those stimuli. In addition, infants born prematurely are at risk for later deficits in attention, and have been shown to have difficulty processing visual information in infancy. Thus, premature infants may be particularly at risk for deficits in allocation of attentional resources. The proposed project will evaluate infants' distractibility during object manipulation longitudinally between 7 and 10 months of age. The project will determine whether individual differences in distractibility are stable over this age range, and whether individual differences exist for distractibility in general or only during focused and concentrated attention. In addition, temperament measures will be obtained to determine whether individual differences in infants' allocation of attentional resources are related to temperamental characteristics. Finally, a sample of infants born prematurely will also be observed to determine whether infants who are at risk for later attentional deficits are more distractible in infancy. The results of this project will provide insight into the development of attention skills in infancy, and further our understanding of the development of children at risk for deficits later in childhood.